ARCHIVED REPORTS XR0000114 - Laserfiche WebLink

Home Browse Search

07/14/90 WED 07 24 FAX 16152815120 PHILIP ENNIRDMiENTAL ]002 i 5 SUm[K"Y OF MAY 1999 WORK A discuss]on of the extent and magnitudc of petroleum impact,ai'sociated health risks, iwd its natural attenuation are discussed in the following sections 5.1 Extent and Magnitude ofJmpaet Results from Philip's May 1999 investigation and monitoring Imlicate a plume of petroleum hydrocarbon impacted groundwatm across groundwater fis n's siximaAAsysho to wn in I-igam 6 and Figure 7,this plume of ungappro ISO feet wide and some 550 feet long,elongated applmximately in the same northeasterly direction as groundwater flow The highest concentrations of T1'H-0 and bcnzerte have been measured in samples collected from well mW-1,which is ,Year the sotvice of Impact Qetroleurli concentrations in groundwater decrease sharPly with distance from the source The lateral extent of Impacted groundwater is largely contained within Earthgmin's property bounce• De lateral extent to the north,south, and west of the source area is well defined by non-detectable concen-rations Jneaswed in groumdwatcr samples collected from wells in those directions At the eastern property boundary,a TPH-O concentration of 100µg1L was measured m one of the groundwater samples collected from C.PT-3,which is located new r Airport Way.However, this same sample dad not eon=n benzene Asculabs charactenmd dIclr TPR-G analysis of the CPT-3 sample as being uric hara,cterishc of a typical gasoline,indicating that it is degraded at flus location..The CPT-3 location is likely near the most downgradient extent of the groundwater plume based on its petroleum concentration,its degraded natuFe,and on the fact that the length of the pl»o(550 feet)correlates well wt i the calculated flow velocity of groundwater (0 13 feet per day)and the time the release was detected D1PE has been,the only oxygenate compound ever detected in groundwater samples collected at this site I)1PE has been oc:cassonally detected iia samples collected from wells MW-1,MW-7, and MW-12 The maximum RIPE concentration evlrr me--aured was 16 µg(L,which was detected in a MW-7 sample collected Jn January 1998 During this last monitoring period,DIPS was not detected,n any groundwater sample (Figure 8) Based on aur 3review of data,it is philip,s opinion that the extent and magnitude of DIPI3 imps in groundwater as of a limiW nature, As discussed earlier,the mass of any residual petroleum impacted soil is relatively negligible Most of the impacted soil had been.overexcavated. The mass of TFH-G mmy 1994 gobsnrraoa 1ftV 99dVn and Groundwsw Mfon[OorbS Rgwrt 'Pro Farthgraius CvmpmaY Paddy 2651 South Airpaft Wray swdctan,California prepared k;Y Philip scnr>ces Corp Pmparod$x THE FaFL'n10nk9a(4MPANY Jude 22,1999 r x U xtas2U2U32M12Mnos9srt"ooc ll